The vast number of castles built by powerful rulers which seem to occupy every strategic rocky outcrop in these valleys bear testimony to the extent to which these valleys were coveted in the Middle Ages. Bolzano boasts an impressive number. When the town was founded beginning in 1170 AD it was originally guarded over by a fortress, Weinegg Castle, the ruins of which were recently rediscovered on the slopes of the Kohlern mountain, along with an exquisite frescoed chapel (closed to the public). Nevertheless the most sumptuous and picturesque castle is Runkelstein (Roncolo), dubbed the ‘illustrated castle’, referring to Europe’s most impressive cycle of medieval secular frescoes which adorn its rooms depicting love scenes and the idealised world of chivalry. Maretsch (Mareccio) Castle – noted for its late renaissance secular frescoes - is singular in that it is situated in the valley floor surrounded by vineyards close to the town centre rather than atop an inaccessible crag. Sigmundskron (Firmiano) Castle sits poised upon a buttress of porphyry rock to the south-west of the town. It has recently been returned to its something approaching its former glory while still remaining a ruin. Built by the Bishop of Trento (who named it ‘Formicaria’) in the 10th century on the site of a former Palaeolithic settlement, it was subsequently owned by the Counts of Tyrol but fell into disrepair in the 16th century. The restoration work adapted the castle to accommodate Reinhold Messner’s Mountain Museum and contains a collection of historic records from old Tyrol documents narrating South Tyrol’s long strive towards the autonomous status in the 20th century. A historic protest rally was held amid the ruins in 1957. Haselburg (Flavon) Castle occupies a similarly scenic position with a commanding view of the Adige Valley as far as Meran, with the imposing Hocheppan Castle dominating the landscape far away on the opposite side of the valley.